This proposal is concerned with problems of the relation between behavior and responses of the visual system, including color vision, meaning, and information processing. The overall goal is to understand the fundamental mechanisms involved in the action of the nervous system and the behavior it mediates, and consequently involves both physiological and psychological aspects. The proposed research is organized around electrical recording of brain responses during specified tasks dependent on controlled visual stimuli. Using information processing experimental designs and computer data analysis techniques the aim is to relate specific aspects of perception and psychological processes (objectively defined) to specific aspects of human averaged evoked responses from the brain. The experimental questions are directed at temporal properties of color vision, semantic meaning, and visual information processing. The clinical significance of this research is that it affords a means of discriminating specific components of central impairment in the visual system and those areas involved in perception, memory, meaning, and higher mental processes and has relevance in ophthalmology, neurology, and psychology.